I am often told by Sales Engineers and Product managers that a Layer 2 Ethernet service is not fit for purpose if the maximum supported frame size is in the 1518-1522 range (enough to support standard Ethernet frames or VLAN tagged frames).

Or in other words: an MTU of 1500 is not enough (see this blog post for my definition of MTU and a short rant on how the term is often misused)

Have you found anything out so far elsewhere? I'm in search of similar information.
–
Stu ThompsonMar 2 '10 at 8:21

I know Aruba APs will send a jumbo frame back to their controller every 120 seconds. I havn't been able to switch it back to the controller(due to old hardware). Other than that I still wonder when/if it's being used. Possibly ISP grade problems?
–
RobertMar 12 '10 at 19:31

A lot of people have posted comments on situation where they use Jumbos locally but not on the WAN. Can anyone comment on this: Would you consider a WAN ethernet link to be broken if it only allowed for a 1500 byte MTU? It seems the consensus so far is no.
–
Russell HeillingApr 1 '10 at 10:53

As for small business, from my own experience, there is little or no need to implement Jumboframes. In other words: there is only a need to implement Jumbo frames if you need to move huge amounts of data.

If I calculated correctly you only need about a quarter of the frames you'd normally need, so your overhead due to using the IP protocol will drop by three quarters.

I cannot imagine, however, there will be much ISPs offering Jumbo frame support. Not to mention the number of hosts offering Jumbo frame support (namely not a lot).

So there seems no need to implement them, other then on the local network if and only if one would have to move large quantities of data.